An adhesive agent which is temporarily fixed by ultraviolet (UV) irradiation and permanently cured by heat is used in many areas (for example, Patent Literatures 1 and 2). Particularly, such an adhesive agent is often used in uses of an image sensor module. When the temperature increases in the manufacturing process of an image sensor, a lens or the like used in the image sensor deteriorates. Therefore, an adhesive agent and a sealing material used in the manufacture of an image sensor are required to have low-temperature curing properties. Furthermore, in terms of production costs, short-time curing properties are also required. An example of such an adhesive agent having low-temperature and short-time curing properties may include a thiol adhesive agent (for example, Patent Literatures 3 and 4). However, it is extraordinarily difficult to provide UV curing properties to the thiol adhesive agent. This is because a curing reaction between an acrylic resin having UV curing properties and a thiol resin is more likely to proceed than a curing reaction between resin (for example, an epoxy resin), other than the acrylic resin, and the thiol resin, causing a pot life to be shortened to a level that the thiol adhesive agent cannot be practically used.
In view of the above-described problems, the present inventors developed a resin composition which includes (A) an acrylic resin, (B) a thiol compound, (C) a latent curing agent, (D) a radical polymerization inhibitor, and (E) an anionic polymerization retarder (Patent Literature 5), for the purpose of providing a photocurable and thermosetting resin composition having a sufficiently long pot life.